Page 264 - AWSAR_1.0

AWSAR Awarded Popular Science Stories
We are talking about it because potentially the answer lies within sulphur. Calcium sulphate di-hydrate (CaSO4.2H2O) is well known to curb sodicity problem among affected soils. So, there is no wonder when we`re picking this up for the solution. But, here`s a twist, and guess what, we`re making our approach environment friendly also. Here`s how...
Steel slag is produced during the Linz Donawitz process or the LD process in an integral steel plant @ 125kg/ton of Steel. This steel slag, also known as LD slag is highly basic in nature, as it is rich in calcium bearing mineral phases like mono, di and tri-calcium silicates along with free lime and some metallic iron. Apart from being used for road construction, steel slag can also be used as a sinter ore fluxing agent. However, at the same time these applications can`t take care of the huge stockpile of this slag at the enormous rate at which it is produced. With the rapid development of steel industry, the global crude steel production reached a stage of 1.623 billion tons in 2015. So, disposal of this huge amount of bi-product generated in the process requires substantial monetary involvement in one hand while loss of valuable resources on the other.
Therefore, value addition of steel slag needs to be explored so as to produce materials having diverse applications. In this context, yellow gypsum (of purity of almost 86%) is being synthesized by atmospheric leaching of LD slag with dilute Sulphuric acid at 100oC.
This yellow gypsum contains quite a good amount of essential plant nutrients like calcium, sulphur in huge proportion, while phosphorus, iron, silicon, manganese, magnesium and aluminum in moderate quantity, with a very minute amount of heavy metal (titanium and chromium) as impurity.
As chromium is needed @15-35 mcg/day to regulated sugar metabolism and fight diabetes in the human body, the chromium content in yellow gypsum, instead of posing problem of Cr toxicity, can be an added advantage, if this element can be accumulated in plants grown with it. This led us to explore the possibility of this product, not only as a weapon to fight sodicity, but also as a source of sulphur in different component crops under a vivid range of cropping system.
Therefore, with the objectives to testify the properties of Yellow Gypsum in different properties of soils under experiment, along with exploring its potentiality as an indigenous source of S, Ca, Mg, P, Fe and Si, keeping the risk of heavy metal loading of the soil in mind. Also, effects of organic manures, conventional chemical fertilizers, bio-fertilisers and management options are under observation.
So, we`ve aimed to design our experiment in four types of soil, that have been collected from sodic belt of western U.P. (Sandila, Lucknow), acidic lateritic soil from Bankura, W.B., saline soil from Sundarbans area of W.B. and alluvial soil from Jaguli, Nadia, W.B. and taken under green house facility of Bidhan Chandra Krishi Viswavidyalaya for pot culture experiment in 216 pots (each having 6kg of respective soils, 6 doses of Yellow Gypsum and 3 doses of Farm Yard Manure as organic manure, all with 3 replications), to be tested under rice-mustard-ground nut and rice-wheat-spinach cropping system.
From a potent environmental pollutant to an asset, we`ve therefore metaphorically planned to raise a phoenix out of ashes, so that one day we can have a beautiful future, with fertile lands and great food with embedded medications to counteract diabetes in the diabetic capital of the world!
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